1. Field of the Invention
Embodiments of the present invention relate to an injection stretch blow mold tooling, system, and process. In particular, embodiments of the present invention relate to a tooling, a system, and a process for forming parisons and articles, such as containers having integral handles.
2. Description of Related Art
Injection stretch blow molding (ISBM) is a technique used for creating various articles, such as plastic bottles and other containers. ISBM processes are performed with an ISBM machine that: injection molds a resin into one or more parisons of desired shape, conditions the parisons in preparation for stretch blow molding, stretch blow molds the parisons into final molded articles, and then ejects the molded articles from the ISBM machine. ISBM machines are generally provided in two types, 3-stage or 4-stage. A 4-stage ISBM machines will generally include an injection station for injection molding the resin into a parison, a conditioning station for conditioning the parison (e.g., applying heat to the parison), a stretch blow station for stretch blow molding the parison into a final molded articles, an ejection station for ejecting the molded article from the ISBM machine, and a rotation plate for transferring the parison and/or the molded article between each of the stations of the ISBM machine. A 3-stage ISBM machine differs from the 4-stage machine in that the 3-stage machine may not include a conditioning station.
Typically, the molded articles formed by the ISBM machine are containers. Such containers will often be manufactured in the form of plastic bottles, with such bottles having a main body and a neck extending up from the main body. Certain bottles may preferably include integral handles that will facilitate the handling and transportation of the bottles. Furthermore, some bottles may be configured to hold significant amounts of fluid or other materials. In such instances, it may be preferred for the bottles' integral handles to be attached to the bottles at two connection points so as to provide for enhanced support during handling and transportation. However, for bottles made via ISBM, such as bottles formed from PET, it is difficult to form integral handles that are connected to the parisons and/or the bottles at two connection points.
For example, it is inherently difficult to injection mold a parison having an integral handle. Certain known processes are used in which a main body of a parison and a handle are formed separately. The body and the handle may then be subsequently connected together. However, the connection points between such separately formed handle and parison lack the inherent strength of an integrally-formed handle. Next, even if a parison can be injection molded with an integral handle connected to the parison at two points, it is difficult, and nearly impossible, to satisfactorily stretch blow the parison into a container. Such difficulty is due to the handle interfering with and/or obstructing the stretch blow process. Specifically, the handle will generally interfere with the inherent stretching capabilities and characteristics of the body of the parison. Additionally, with the handle connected to the parison at two points, the two points will stretch apart from each other during the stretch blowing process, such that the handle must similarly stretch.
As such, it would be desirable to have ISBM tooling, systems, and processes for producing molded articles (e.g., containers) with integral handles, and in particular, for producing molded articles that include integral handles that are secured to the molded articles at two connection points.